Obesity is a complex, medical disease affecting more than 30% of the population in the United States. Obesity affects an individual's personal quality of life and contributes significantly to morbidity and mortality. Obese patients, i.e. individuals having a body mass index (“BMI”) greater than 30, often have a high risk of associated health problems (e.g., diabetes, hypertension, and respiratory insufficiency), including early death. In the United States, approximately 280,000 deaths annually are attributed to obesity and obesity-related diseases. In the case of morbid obesity, studies have shown that conservative treatment with diet and exercise may be ineffective for reducing excess body weight. In addition, specific diets, medications, behavioral modifications, and exercise programs have over a 95% failure rate in morbidly obese individuals. Consequently, surgery is often the most effective means of treatment. “Bariatric surgery” is the field of surgery that treats people who are so overweight that they are suffering health consequences due to the excess weight. The surgery usually involves operations on the stomach to restrict one's ability to eat, or on the small intestine to restrict the absorption of ingested food. See M. Deitel, “Overview of Obesity Surgery,” World J. Surg., vol. 22, pp. 913-918 (1998).
A successful bariatric surgery results in a maintained weight loss of greater than 50% of excess body weight and in an increase in patient wellness. An important factor for success is a long-term relationship between the patient and a medical team, which includes the doctor performing the procedure, a dietitian, a psychologist, and a physical therapist. While current bariatric surgery may assist patients in reducing food intake, it may also increase medical risks due to complications inherently associated with surgery, including complications of anesthesia, surgical procedure, wound infections, dehiscence, stomal stenosis, marginal ulcers, thrombophlebitis, and pulmonary problems.
There are several bariatric surgical procedures for treating morbid obesity. One procedure for treating morbid obesity is referred to as a “biliopancreatic diversion.” Biliopancreatic diversion surgery is a reduction of the stomach volume and a diversion of food from the stomach to the final segment of the small intestine, bypassing the beginning and middle portions of the small intestine to limit the amount of nutrients and calories absorbed by the body. This procedure removes about one half of the stomach, and then connects the stomach to the last 250 cm of the small intestine. Disadvantages of this surgery include patients suffering from protein malnutrition, anemia, gastric retention, diarrhea, abdominal bloating, and intestinal obstruction. See P. Marceau, et al, “Malabsorptive Obesity Surgery,” Surg. Clinics of North America, vol. 81(5), pp. 1113-28 (2001).
Another bariatric surgery, “gastric bypass,” is a bypass connecting the lower compartment of the stomach to the initial portion of the small intestine. This procedure limits the amount of food that can be ingested at one sitting and reduces absorption of food across the small intestine. In addition to surgical complications, patients may also suffer from acute gastric dilation, anastomotic leak, anemia, and dumping syndrome. See R. E. Brolin, “Gastric Bypass,” Surg. Clinics of North America, vol. 81(5), pp. 1077-1096 (2001).
A third bariatric surgical procedure is “gastric banding,” which constricts the stomach to form an hourglass shape. This procedure restricts the amount of food that passes from one section to the next, which induces a feeling of satiety. A band is placed around the stomach near the junction of the stomach and esophagus. The small upper stomach pouch is filled quickly, and slowly empties through the narrow outlet to produce a feeling of satiety. In addition to surgical complications, patients undergoing this procedure may also suffer from esophageal injury, splenic injury, band slippage, staple line disruption, reservoir deflation/leak, and persistent vomiting. See E. J. DeMaria, “Laparoscopic Adjustable Silicone Gastric Banding,” Surg. Clinics of North America,” vol. 81(5), pp. 1129-44 (2001).
A fourth bariatric surgical procedure is “vertical-banded gastroplasty,” which restricts the volume of the stomach by using staples. In this procedure, staples are placed in the upper stomach region to create a small pouch with a narrow outlet to the remaining portion of the stomach. A lap-band is placed around the narrow outlet to provide support and inhibit stretching of the stomach. In addition to surgical complications, patients undergoing this procedure may suffer from vomiting, ulcers, band erosion, and leaks. See C. Doherty, “Vertical Banded Gastroplasty,” Surg. Clinics of North America, vol. 81(5), pp. 1097-1112 (2001).
U.S. Pat. No. 6,102,922 describes a device and surgical method for reducing the food intake of a patient by forming a restriction in the stomach using a band. In one embodiment, the band is looped around the esophagus and a portion of the stomach is pulled up through the band loop. This forms a small stomach pouch and a narrow outlet to the remaining portion of the stomach. This allows for a quick filling of the small stomach pouch, and a slow emptying of the stomach through the narrow outlet to produce a feeling of satiety.
U.S. Pat. No. 6,475,136 describes a device for treating heartburn and reflux disease by restricting the amount of food flowing into a stomach or an esophagus, comprising a restriction device (a sphincter or a cuff) that can be adjusted. In one embodiment, the restriction device performs like an artificial sphincter that opens and closes the food passageway in the stomach. In an alternative embodiment, the restriction device comprises an adjustable cuff, a clamp, or a roller to bend or rotate the esophagus or stomach to close or almost close the junction between the stomach and esophagus.
U.S. Pat. No. 4,246,893 describes a device and method for treating obesity by compressing the stomach and reducing its capacity using a single adjustable distensible device (e.g., a balloon) whose volume can be adjusted from an external port.
U.S. Pat. No. 5,993,473 and WO 99/2418 describe a device and surgical method for treating obesity by decreasing the volume of the stomach by using a single expandable device placed inside the stomach cavity.
U.S. Pat. No. 4,694,827 describes a device and method for controlling obesity by deterring ingestion of food using a single balloon that is placed inside the stomach.
U.S. Publication No. 2002/0188354 describes a device for treating obesity by inserting an hourglass-shaped device into the junction between the stomach and the small bowel, which delays gastric emptying of food.
U.S. Pat. No. 6,511,490 describes a device for the treatment of morbid obesity by restricting food passage in the stomach by placing an inflatable band around the stomach to create a pouch with a small opening adjacent to the esophagus. The inflatable band is secured and then inflated until the appropriate sized opening is achieved.